OMAHA, NE—May 2. 2019— Monster Energy Supercross fans from across the globe can now bid on autographed items donated by Supercross athletes, available in an exclusive online auction with proceeds benefitting St. Jude Children’s Research Hospital.® The auction, which is available online only, includes more than 200 unique items up for bid until Monday, May 6 at 5 p.m. Central….